Technical Tip: Auto RP on FortiGate

[fwilliams]

Description	This article discusses how to implement auto-discovery of Rendezvous Point (RP) in a multicast network involving FortiGate.
Scope	FortiOS.
Solution	In a multicast network (PIM - Protocol Independent Multicast), a Rendezvous Point (RP) is required for receivers to discover the sources that are sent to a particular multicast group. It can be said that RP is the meeting point between the multicast source and the receivers. To make the discovery or the configuration of an RP in an automatic version, instead of configuring it statically (similar to the comparison between static and dynamic routing) a protocol called Bootstrap Router (BSR) was developed. BSR for PIM is detailed in RFC 5059. BSR is similar in function to a Cisco proprietary protocol called 'Cisco Auto RP'. For a multicast network to propagate RP information automatically, and enable BSR on the devices participating in PIM, FortiGate with the highest bsr-priority will be elected as RP. BSR Configuration: config router multicast     set multicast-routing enable         config pim-sm-global             set bsr-candidate enable <-- Allow this router to function as a BSR.             set bsr-interface portx             set bsr-priority 255 <--- Highest priority.             set bsr-allow-quick-refresh enable             set register-rp-reachability enable         end         config interface             edit portx                 set pim-mode sparse-mode                 set rp-candidate enable                 set rp-candidate-priority 255                 set rp-candidate-interval "1 - 16383 sec"                 rp-candidate-group “string” <-- Multicast groups managed by this RP. Define the group in ACL.         end end Note: There can be more than one active RP in a multicast network at the same time; each RP manages a certain multicast group.